Furnace went out at 4 AM - Montana Owners Club

dsprik · 01-10-2010, 01:25 PM

In this weather, that is not good. We switched to our electric heaters, but the belly was left unprotected when we do this. This morning, after playing with the thermostat - searching the MOC extensively and resetting the thermo - I came across a post that mentioned pulling the outside panel off the furnace and look for flashing red lights.

Sure enough I had a flashing light. As I was looking around I yanked on some wires and lo and behold the furnace fired up. As I continued to tug on wires, it intermittently lost and gained connection. I discovered an upside down breaker switch that seemed to be the culprit. This breaker is very difficult to see and is horribly positioned for anyone accessing this area to even see. I would not have even known it was there if I hadn't followed the wires down.

Anyway, this rocker switch looks similar to a standard 12v rocker switch that we use in our inside electric panel by the door. I pulled it and went to Home Depot and CW to find a replacement. Neither had one, so I picked up some new connectors to replace the ones on the wires, thinking that maybe the connectors were bad.

Putting on the new connectors, I reset the switch and set the thermo and it fired up. I was quite happy as the furnace fired up and ran normally. It ran and shut down as it should have when it reached its set point.

Waiting for it to kick back in again - it was windy and 39 outside - I soon realized that the furnace was not going to kick on again. I pulled the panel and the red flashing light was there again. I turned the switch off then on and the furnace fired immediately.

However, it settled into a cycle of running normally only once and I then had to go out and reset the breaker. Concerned that I may have a bad board, I went to my neighbor to borrow a 12v rocker switch. I used this to jump the breaker. It worked. Furnace is cycling normally.

This obviously is not an ideal setup and I need to try to find a 15 amp breaker switch tomorrow. If I can't find one at the camping stores, I will have to innovate and wire in another situation with an inline 15 amp breaker or fuse.

Another educational experience today.

richfaa · 01-10-2010, 01:43 PM

Dave.. I will bet RV connection will have or can get that guy for you..and I want one for my spare parts bin..

dsprik · 01-10-2010, 01:45 PM

They were closed today, Rich. I plan on running up there tomorrow first.

wingerphil · 01-10-2010, 02:16 PM

Dave,

Try this. When the furnace does not cycle and the red light is flashing rap on the outside blower case and see if it starts it up. Mine was doing the same thing you describe and it was a bad sail switch, raping on it causes the switch to close (and the furnace will run/ignite). I could get mine to work by resetting the breaker switch or by tapping on the case(sometimes I had to do both). I replaced the sail switch and it fixed the problem. Your breaker switch may be bad, but it could be the sail switch and this could confirm one or the other. The sail switch is mounted to the inside of the outer blower casing. If you have to replace it, remove the 4 screws holding the casing on, unplug the wires and remove the case. The switch only cost me $7.00 and about 8 months of total frustration.

Here is a link to my blog with a pic of my sail switch that was bad.
http://workinrvers.blogspot.com/2009/12/cold-again.html

dsprik · 01-10-2010, 03:07 PM

Thanks, Phil. I remember the posts on the sail switch now. IIRC this was a common problem with many MOCers? I will check this out, too. So far the furnace is working as it is supposed to - with the breaker jumped - but for only $7, I can sure replace a potential problem (sail switch) before I have one...

Bill-N-Donna · 01-10-2010, 05:01 PM

Thanks for posting
Good information!

ols1932 · 01-11-2010, 01:46 AM

wingerphil,
That procedure was actually given to me by a mobile RV Doctor who said he uses it all the time. It works! Reminds me of some of our radio receivers we had in the military. We actually put a post-it note on one that said, "hit here". We were only joking of course because the big boss wouldn't have liked that.

Orv

wingerphil · 01-11-2010, 01:57 AM

Orv,

I figured it out by accident when I tapped it with the handle of my screwdriver. By the time I finally got a diagnosis that the sail switch was the culprit I was ready to use a sledge hammer to "tap" it.

boylanag · 01-11-2010, 02:09 PM

We woke up at 4:00AM Sunday morning in Memphis with no electric or furnace and outside temp 11, inside 39. We were lucky, Dave. It was in the power pole. Just unplugged and replugged into a neighboring box and all was well. People all across Tennessee have been accusing us of bringing Michigan weather with us. Thanks, all, for the great info!

dsprik · 01-11-2010, 04:19 PM

I went to Camping Connection twice today. The first time the parts guys figured that this part would be OK to be replaced by my standard rocker switch. So I came home and called Atwood Tech Support and Sue told me to go back and tell them to order the part as it is a special switch. So Richfaa and I went back to CC and ordered a part for each of us.

The switch has this number printed on it: W51-A151A1-15. My Atwood furnace model is 8535-IV. The actual Atwood part number needed to order - and you will need this as both CW and CC ended up scratching their heads on what this was - is 34013.

dsprik · 01-11-2010, 04:26 PM

Jim, We lost our electric at midnight a few nights ago with 25° weather and wind. We had to go straight battery. I was very happy as our little interstate battery ran our furnace and lights for 8 hrs. First time we had to do that. Didn't know what to expect, but I knew through being a longtime MOC reader that it is done and these units are actually designed to be able to do this. I was very happy with how these Montanas handle all situations and adversity...

Briarglenn · 01-22-2010, 09:43 AM

Not a reply, but a question. We seem to have a similar problem on our '07 3400 RL that only occurs when it's wet outside and raining. Our flashing code is for an "Ignition Lockout Fault". We have had this problem since we bought the trailer and the authorized repaired services cannot replicate the problem. I'm willing to replace the sail switch and check it out, but could use some advice or secrets on accessing it or reassembling. Thank you.

dsprik · 01-22-2010, 03:47 PM

John, could you be a little more specific on what happens? Does your furnace not cycle? You could pick up a 12v rocker switch and replace your "breaker" switch to see if that cures the problem. As far as installing a new sail switch, I haven't done that yet. Someone earlier referred to the procedure, though...

Briarglenn · 01-22-2010, 05:35 PM

Thanks for the reply. The furnance cycles ok. in that it tries to ignite 3 times then shuts down. I can be at the furnance and switch the rocker switch and it will cycle again. It is not a hard off/on when I reset the switch, it is just a touch, then it starts the cycle again.

John

dsprik · 01-23-2010, 01:52 AM

I jiggled my bad switch and it acted like there was a loose connection in it. The furnace was running when I did it and the power to it flickered "on-off-on-off-on" very quickly. I was afraid it was going to lose power without the fan having a chance to cool it off.

Chip · 01-23-2010, 02:49 AM

I have had a similar furnace problem of not cycling. My dealer replaced the limit switch last fall. Camper is in storage until spring. I am going to order the sail switch as well.

Two questions:
1. Where is this red light mentioned in above post and what part is it on? I can't find it in the manual.

2. The Breaker Switch; Is this just an on-off switch or is in an actual breaker as well?

Thanks,
Drew

Briarglenn · 01-23-2010, 03:29 AM

The 'red light' is located on the circuit board and somewhat hidden by the white multi plugs into the board. Look above the furnance. The codes are on the blower housing. Now that the rain has stopped, I head over to Quartzsite to see if I can pick up a switch/circuit breaker and a sail switch. Will keep u posted.

dsprik · 01-23-2010, 06:08 AM

Quote:

quote:Originally posted by Chip

Two questions:
1. Where is this red light mentioned in above post and what part is it on? I can't find it in the manual.
My board was upside down and you had to bend down a little and look up. If the red lights are flickering/flashing, you won't have any trouble find these little LED lights soldered to the board.

2. The Breaker Switch; Is this just an on-off switch or is in an actual breaker as well?
I talked to Atwood tech service directly - after the camping store parts guy told me I should be alright with just the standard rocker switch I had put in - and she told me no, that's not quite true. I ordered the switch and it should be here any day.

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